VOL. X V I I .
MARCH,1895.
No. 3.
THE JOURNAL OF THE
A M E R I C A N CHEMICAL SOCIETY. THE SYNTHETIC FOOD OF THE FUTURE.' BY HARVEYW. WILEY.
HE problem of human nutrition is the great groundwork of sociology. I use the word nutrition in its broadest sense, including clothing and fuel, which, while not as essential as food to life, are quite .as important factors in civilization, Until within a few years the study of nutrition aiid the means of providing it have been deemed the exclusive function of agriculture. I n the development of this idea, we have seen springing into existence in all parts of the civilizcd world, within the past twentyfive years, colleges of agriculture and agronomic experiment stations in large numbers. Especially in this country have we seen the greatest activity in this line. I n all the states and territories. fostered by the federal government, schools have been established in which instruction in agriculture has been made a fundamental branch of the college curriculum. There are fiftyseven agricultural experiment stations in the United States. Each state and territory has at least one. Louisiana has three, Alabama, Connecticut, Massachusetts, New Jersey, and New York each two, and the Department of Agriculture two, one in Florida and one in California. For the support of the state and territorial stations, Congress has made a n appropriation for the fiscal year ending June 3oth, 1895, of $745,000 and for the Department stations $IO,OOO,in all $755,000. T h e agricultural colleges in the states and territories have also been endowed by 1Retiring Address of Harvey W. Wiley a s President of the Society, Boylston Hall, Halvard University, Dec. 28, 1%.
Ij6
H . I R V E I - W . WIL.EY.
grants of public larid proportionate i n esteiit to the numbers of 'rile a l l n u a i molley senators :uid representatives i i i c:t)iigre value of these grants varies n ith their exteilt ami the \vistloin with which they h:~i-elieeii inrwtetl, ljut the total sum is approxiiiiatelJ. :i million aiid a h x l i (Iollu-s. Iii aciditioii to this a siiiii of nioiiey is graiitetl aiiriuall~.t o each agricultural c ~ l l c g e directl!? from the treasur>.. :iritl tlii; si1111 ic to lie immxtsecl at t!ie rate of $1000 per annum uiltil it aiiiouiits for each institution to Izj,oooa year. This amount \viU \)e reached i n five years. Xt present t h e total siiiii so grnntctl is tiearl>- a tiiillioii tlollars. ant1 it \vi11 soon be a niillioii :ind n qunrter. Tlit total 'iiiioiiiit of the financial aid t h u s granted tlirectl!. from the treasur). to the agricultural colleges xiid experiineiit stations i. at the present time approximately three niillion and 3 quarter dollars annually. To this must 1)e added the airinwit given directly bj- the states and arising from private endo\vinents-a s u m of !io inconsidei-able importance. 111 all it inay lje said tliat about four million dollars i n this countr!. are annually devoted to the promotion of agricultural ancl allied education aiid research. a sum more liberal than that devoted by any other countr), to siinilar objects. The iiatural result froin such iiivestigations is a n increase in soil producti\.eiiess, the reclamation of Ia~ids supposed heretofore to be unfit for tillage and a greater eco!ioniy of food production. T h e suppl!- of human footl. therefore, appears to more tlian keep step ivith the increase i n population ancl food consulriptioil. 111 so far as econoinic reasons extend, there is no occasion to look outside of scientific agriculture for the supply of hunian footl. Rut another view is presented of the subject of a more strictly scientific aspect. based on the reniarkable progress which has been made in the past fe\v years in the domain of syiithetic chemistry. T h e ).ear 1828 niarks a nc'\v era iti the history of chemistry. I t was in this year that Wohler succeeded in making synthetic urea b y the union of q m i i c acid and ammonia. T'rea is not of a high order of organic bodies ; in fact, it is a result of retrograde action in the living organism arid the consequent result of the breaking down of higher organic bodies ; yet its artificial forniatioii was a brilliant victory of chernical niethotls. a I ~ o l d;ind successful charge
THE SYNTHETIC FOOD OF THE FUTURE.
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on the breastworks of organic compounds. To change the figure, it was the crossing of the dead line which had been drawn previously between the living cell and the inanimate crucible. T h e line once having been crossed, the old distinctions between the organic and the inorganic world have been completely obliterated. With them have gone also the divisions which were supposed to separate the animal from the plant. It is now known that animals do not get their entire nourishment from so-called organic nor plants from inorganic compounds. Many plants, especially those free of chlorophyl, live alone on organic compounds. Especially noteworthy among these, from the character of the chemical activity which they manifest, are the T-egetations of a bacterial nature, living largely on organic products. Even the green plants first fabricate the inorganic elements into organic compounds before taking them into their tissues. T h e green cells are the tiny kitchens in which the meals of the plant molecules are prepared. Without dwelling on further details of this subject, it is sufficient for the present purpose to state that the progress of modern science has entirely changed our ideas respecting the sharp lines of division which were formerly thought to exist between the animal and vegetable, and between the nature of artificial chemical compounds and those produced by biochemical action in the living organisin. We stand, therefore, face to face with the fact that it is possible to produce, by artificial means in the laboratory, compounds which have heretofore been the results of exclusive biocheniical functional activity of living organisms. One remarkable fact in connection with Wohler’s synthesis of an organic compound is of interest here. While all the cheniical world wondered at Wohler’s achievement, nearly fifty years elapsed before this rich field of cheniical progress was further cultivated to any extent, with the single exception of the synthesis of acetic acid by Kolbe, in 1845. But since that time remarkable progress has been made. It is not my purpose here to recite in detail the synthetic accomplishments of Berthelot, KekulC, Kolbe, MaunienC, Baeyer, Hoffmann, Frankland, Ladenberg, Fischer, and many other celebrated workers in this field.’ 1
tion,
See Rise and Development of Organic Chemistry, by C. Schorlemmer, revised edi1%.
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HARVEY W . W I L E Y .
For the purpose of the present paper, only two points in organic chemical synthesis need be considered; ziz., first, the economy of tlie process, and second, the probability of tlie production of food compounds suited to tlie nourishnient of man. In respect of the first point, we finti many illustrative examples of synthetic products which are furnished at so small an expense as to practically exclude from the market the corresponding natural articles. Among these may be mentioned salicylic acid made artificially by Kolbe's' process. Salicylic acid occurs as a natural product in the flowers of .'?pirc.a zdvzaria and as a methyl ether in the oil of wintergreen (C;auZlhcriaprocismbe,zs). It can be formed by synthesis in various ways, as, for instance, by fusion of salicylaldehyde with potassium hydroxide. Salicine, couniarine, indigo, cresol, or toluenesulphotiic acid may be substituted for tlie salicylaldehyde. %%en phenyi carbonate is heated with a caustic alkali, salicylic acid is also produced. I t may also be obtained when an alkaline solution of phenol is boiled with carbon tetrachloride. But none of these processes, although of great interest cheniicall!~. have any value coinniercially save that of Kolbe, or more properly, Koll)e and Lautematiii, which consists of passing carbon dioxide into sodiuni plienylate. But it will be observed that the plienol which is tlie base of the process, is itself an organic conipound. or the result of the destructive distillation of ail organic cornpound produced by nature. I t is not impossible to produce phenol by artificial s1.nthesis. It is said that by surrounding the points of an electric arc light with hydrogen that carbon and hydrogen conibine to foriii acetylene, C,H,. According to Herthelot,' fuming sulfuric acid absorbs acetylene and the product so formed fused with caustic soda forms phenol or sodiuni phenate. But it needs no further illustration to show that a phenol formed i n this manner could never, on account of its great cost, be used for the conimercial manufacture of salicylic acid. A distinction should be made in this riiatter between the foriiiatioil of possible food products by synthesis from existing organic natural bodies, and the synthesis which begins with the inorganic elements themselves. The transformation of one organic 1 J . p u a k t . Chenr., a , IO, 93. a Cunipf. r e n d . . 68, 539.
THE SYNTHETIC FOOD OF THE FUTURE.
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body into another of greater value to human industry is quite a different matter from the building up of organic bodies without the help of a living organism. Berthelot himself, who is now the apostle of synthetic foods, summarizes the steps which will probably be traversed on the way which is to end in the substitution of the chemist for tlie farmer : I . Hydrocarbons, obtained by the union of hydrogen and carbon. 2 . Alcohols foriiied from the hydrocarbons in various ways. 3. Aldehydes and acids obtained from alcohol by oxidation. 4. Amides produced by the action of ammonia on the alcohols. 5. Alkaloids formed by the action of ammonia on the alcohols and aldehydes. But even granting tlie fullest development of such a scheme, the impartial observer will be compelled to admit that there is still an immense gulf between the best of the products foriiied and human food. I n the case of medicines and drugs, perhaps the case is more hopeful. In so far as niere tratisforniation of one organic substance into another of greater therapentic value is concerned, riiuch progress has already been made. But in nearly all of these cases the products are obtained by the splitting up of more coniplex into less complex molecules. I n other words, it is a retrograde synthesis and not a constructive one. A mere list of reiredies iii coninioii use, which have been formed in this way, would forni an extensive index of pharmacy. Both Liebig and Wohier, as early as 1837, foresaw this advance in syiitlietic chemistry and predicted the synthesis of alkaloids and aiitiseptics and even of sugar. Founded on the classical researches of Willianisoii on etherification has been built the art of forniing by synthesis a great variety of flavoring matters for food and drink. I n the strict sense of the term, these condiments are not foods inasiiiuch a s they are not subject to digestion and do not take any part in the nourislinient of the tissues. They have a nearer relationship, however, to the purpose of this address than the bodies already mentioned. T h e slow natural oxidation of the alcohols in fernieiited and dis-
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HARVEY W . WILEY
tilled drinks, giving rise to ethers of delicate odor and flavor, is an expensive process, and synthetic chemistry has boldly come to the aid of nature. T h e essences of fruits and flowers are now elaborated in great numbers in our laboratories and supply to a certain extent the natural products. With the aid of ethyl alcohol, burnt sugar, and a collection of artificial essences, the skillful manipulator will mix, in short order, drinks which resemble bourbon and old rye, madeira and sherry. T h e pure fruit flavors of many soda-water fountains could easily prove an alibi in respect of orchards. In the great majority of cases these essences are also the products of retrograde synthesis, or have for the base of manufacture an alcohol derived from the fermentation of a natural sugar. While it is true that they can be manufactured at a lower cost than attends their natural production, and while they are used as condiments in foods and drinks, yet in no sense can they be regarded as a step toward the preparation of foods from inorganic elements by purely chemical means. T h e priticipal artificial flavoring extracts are the derivatives of the fatty acids, especially the ethers and aldehydes. T h e ethereal salts of acetic, valerianic, benzoic, salicylic, and butyric acids, are the most common of these bodies. Methyl, ethyl, and amyl are the bases most usually found in the above compounds. Vanillin has also been made synthetically. Analysis showed that this natural product of the vanilla fruit was niethylprotocatechuic aldehyde. This knowledge led to its artificial production. From turpentine is derived a perfume turpineol which is known as “lily of the valley.” T h e artificial production of musk and of the perfume of the violet have also been accomplished. Whether or not these bodies are injurious to health is a question whose discussion can not be entered into here. I n the case of one of the best known of these condiments, and one which is not of ethereal origin, it may be said that its use in foods is prohibited in some countries, whether it be used as a sweetener or as an antiseptic. I n justice to saccharin, howe\;er, it should be stated that repressive legislation against it has been quite as much due to a feeling of jealousy on the part of beet-sugar producers as to a suspicion of unwholesomeness 011 the part of the medical fraternity. Certain it is, however, that, even as asweet-
THE SYNTHETIC FOOD OF THE FUTURE.
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ener, it will never take the place of sugar and becauseof its antiseptic properties it must necessarily interfere to some degree with the action of the digestive ferments. I t is not necessary to take up in detail other synthetic compounds which have attained a commercial success. T h e artificial dye stuffs are types of these bodies and illustrate, in a most brilliant manner, the progress of chemical synthesis based on the knowledge of the internal constitution of organic compounds derived from analytical investigations. But even the most enthusiastic believer in the future triumphs of chemical science will fail to find anything more than an inspiration in these achievements in respect of the production of foods. In all cases of coloring matters, original organic compounds derived from living cells, or the products of their destruction, have served as the bases of the processes. Without an elaborate review of this field therefore, and which, moreover, has already been made,' we pass a t once to consider these achievements in synthesis which relate directly to the matter under consideration. Along two lines of especial interest to food production, synthetic chemistry has made its greatest advances ; viz., the production of glycerides and of sugars. Wurtz' has described a method of synthesizing glycerol, which, in logic, would be called arguing in a circle. HCHBr Tribronihydrine, CHBr, is deconiposed with silver HCHBr acetate forming triacetine. This is saponified by baryta yielding glycerol. T h e tribromhydrine, however, is first prepared from glycerol or rather from allyl iodide made from glycerol. At the end of this long synthesis, therefore, the chemist is exactly on the spot whence he started. Friedel and Silva3, however, niade glycerol in a different way. Trichlorhydrine is prepared from propylene chloride and saponified by heating with water. T h e propylene used is made from acetone. Wagner' produced glycerol by oxidizing allyl alcohol with potassium permanganate. ' B e r d . chem. Ges., 1892, 24, 1007. * A n n . Chem. (Liebig), 102, 339. 8 BUN.Soc. Chim.. ao, g8: 4 Berd. chem. Ges.. 2 1 , 3351.
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H A R V E Y W . WILEY
Glycerol has also been formed synthetically by other investigators, but the principles involved are not greatly different from those set forth. T h e first notice I have seen of the artificial formation of a f a t is in a paper by Pelouze and Gelis' published i.n 1844. It is said that by gently heating a mixture of glycerol, butyric acid, and strong sulphuric acid, and afterwards diluting with water a yellowishoilseparates. Thisfatisnotsoluble, oronlyrjliglitlyso, in water. I t is soluble in all proportions in strong alcohol and in ether. Caustic potash breaks it up into butyric acid arid glycerol. I t may be formed a t ordinary temperatures by passing a current of hydrochloric acid into a niixture of butyric acid and glycerol and afterwards diluting. T h e authors thought this body to be the butyrine discovered in butter by Chevreul. Its great solubility in alcohol would lead us in this day to :juppose that the body was not a true butyrine. Our piesent knowledge of the n a t u r d fats is based almost solely on the classic researches of Chevreiil. While the work of Chevreul was purely analytic i i its character, the knowledge of the constitution of fats which it disseminated has been the foundation on which all subsequent structures have been built. While at the present day chemists do riot recognize the existence of rnargaric acid and margarine, all t h e other fatty bodies described by Chevreul have been found to have substantially the constitution which he assigned them. Berthelot's first important contribution to the synthesis of fats was presented to the French Academy of Sciences on the j t h of September, 18j3. I t was entitled I ' Me~noiresur les cornbiiiaisoils de la glycerine avec les acides et s u r la synthese des principes iminediats des graisses des aniniau.x. ' I z From Berthelot's paper we learn that glycerol was discovered in 1779 by Scheele3 in making lead plaster. Fourci-oy was the first to theorize on the nature of fats'. Berthelot regarded the formation of soap as due to the affinity of oils for alkali.5 A n n . chim.phys., 1844, [ A ] . IO,434. A n n . c h I m , p h y ~ 1854, ,, [3]. 41,216. 8 Optisrula. a, 175. 4Sy~Lv1rrdes connaisiancps rhzmiques, 7, 142,323, 329, atid 334. 6 C h e v r r u l , A n n . chim.phyA..88, 226. 1
2
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Fourcroy in his work on the fat of cadavers, substituted another idea for this rational one, thinking the formation of soap due to the oxidation of the oil under the influence of alkali and air. H e classed the vegetable oils, waxes, cadaveric fats, fats liberated from soaps by acid, cholesterine, etc., together under the name " adipocere."' I n 1815, simultaneously with the discoveries of Chevreul, Braconnot rejected the ideas of Fourcroy, saying : ' I When tallow is agitated with acid or alkali, the three constituents, hydrogen, oxygen, and carbon, which had been in a state of equilibrium, separate and rearrange themselves in another order, giving rise to adipocere and to a very fusible fat, soluble in alcohol.' Pelouze produced sulphoglyceric acids and phosphoglyceric acids and together with Gelis* he made butyrine, the first artificially prepared fat. Berthelot has generalized this work by combining glycerol with both organic and inorganic acids. T h e bodies produced are, as a rule, neutral and incapable of directly uniting with alkali. Some reproduce the natural fats. Sfearins.-Stearic acid, melting at 70' and prepared according to the method of Chevreul,' forms with glycerol three neutral bodies, mono-, di-, and tristearin. T h e last is identical with natural stearin. To make monostearin ; Berthelot heats equal parts of glycerol and stearic acid to 200' for thirty-six hours in a sealed tube. T h e body formed is insoluble in glycerol and readily separates from the excess of this body. It may be purified by heating to 100' with ether and quicklime to deprive it of excess of stearic acid. To make distearin: This body may be formed by heating equal parts of glycerol and stearic acid to 100' for 114 hours, or to 275' for seven hours. I t may also be formed by heating natural stearin to 200' for twenty-hours in the presence of glycerol. Another method is to heat monostearin to 260' for three 1 A n n . chim.phys..3, 129 : Ibid, 5, 154 ; Ibid, 8, 17, 23, 31, and 67. a A n n . chim.phys.,gj,271. 8 Sur la ncide sulfoplycerique, Comgt. rend., 11, 718 ; Sur la butyrine, Nouvelles, A nn chim phys.-IO, 455. 4 Kecherches sur les corps gras, page 206.
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HARVEY IV. WILEY.
hours in the presence of three parts of stearic acid. However formed, it is to be purified by tlie treatment with ether and lime. T o make tristearin : This body is obtained by heating monostearin to 270' for three hours with fifteen or twenty times its weight of stearic acid. Water is eliminated. 'I'he product is to be purified with ether and lime. Tlie properties of natural and artificial stearin coincide as nearly as call be expected, corisidcring the fact that natural stearin is never obtained pure. Tlie nearest approach in properties by natural stearin to those of the artificial, was that shown by a preparation made by P. Duffy' who purified it by thirty-two crystallizations. The acid prepared by saponification, etc., from the synthetic stearin had the same melting-point as that originally eniployed. .l~~vguri?ies.-Margaric acid from huinaii fat' forms two neutral combinations with glycerol, monomargarine, and trimargarine. To make mononiarganne : Monomargarine may be prepared by heating a mixture of glycerol and niargaric acid to zoo' for twenty-one hours or to 100' for 106 hours. T h e reaction takes place with great readiness, i n fact the synthesis is easier than that of any other fat. T h e same body or a similar one, is formed by simple contact of the constituents at ordinary temperatures for three tnoiiths, though in very small quantity. A margarine is also formed by heating a mixture of iiiargaric acid aiitl glycerol saturated with hydrochloric acid, to I O O ~for soiiie hours, but it is a1w a!*s coilt ami na t ed with clilorh y dri ne. Triinargarine is formed by heating iiioiioniargarine to 270' for seven hours i n the presence of excess of iiiargaric acid. The fat acid separated from it by saponification, etc., had the sanie nielting-point as that originally employed. Palmitim.-Three palmitins were formed in the way employed for the preceding fats. Olez'm.-Three were formed. T h e oleic acid eniployed was purified by the method suggested by Gottliebe.' The commercial acid was twice chilled and filtered and then converted into a potash soap. T h e soap was dissolved in twice its weight of alcoSoc., Jan.. 1853. pages 303,3 9 . 310. Chevreul, Recherch,es, s u r les corps gras. page 59. 8 A n i i . dev Chem. u. Phavm., 57, 93. 1 Q u u i - f . J o u r . Chert.
2
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hol, filtered cold, and precipitated with barium chloride. T h e barium soap was recrystallized from boiling alcohol (one liter of strong alcohol dissolves five grams), and then decomposed by tartaric acid in an atmosphere of hydrogen. Valerines, butyrinesand acetines were formed in the same general manner. All these fats could also be produced, and more easily, by heating the components to 100" in the presence of an auxiliary acid, such as sulphuric, hydrochloric, tartaric, phosphoric, etc. Triacetine has also been formed by Bottenger' by the action of acetic anhydride on glycerol in the presence of acid potassium sulphate. In this direction the work of molecule building has been carried a step further in securing the construction of a higher glyceride containing phosphorus. Hundeshagen' has succeeded in preparing a substance similar to lecithin, which is one of the essential constituents of cell plasma. I n this work he followed first in the steps of Berthelot in securing distearin (distearylglycerol) by heating stearic acid with an equal volume of anhydrous T h e purified glycerol for thirty hours in closed tubes at 200'. distearin, heated to I IO' with metaphosphoric acid or phosphoric anhydride, gave the desired phosphorus compound. Numbers of the salts and derivatives of the distearylglycerol phosphoric acid have also been prepared and studied. I n the matter of sugars greater progress has been made. T h e elder Thenard, more than fifty years ago, proposed a scheme for the direct production of sucrose by the condensation of carbon dioxide, water, and ethylene. Kiliani, Tollens, and many others have made important contributions to this work, but by far the most important advances in the synthesis of sugars have been made by Fischer. His work has been most thoroughly reviewed in this country by Keiser3 and Stone.' Fische? has also pubStarting with formaldehyde lished a resume of his work. and passing through glycerol and acrolein, Fischer, by a series of beautifully conceived researches, has succeeded in forming, Chem., 163,359. p r a k t . Chern., ueue Folge, 10, 2x9. 8 A m . C h m .J . , 11, 277, aud 1 1 , 357, 4 A g . Science, 6, 166. 6 Ber d . chem. Ges., 13,2114,and a7,3189. 1Ann
21.
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HARVEY W. WILEY
by synthesis, a large number of sugars, some of which have not been discovered in nature. For the details of this work, the reviews mentioned can be consulted. Lately in the same direction, another step has been taken. Fischer and Bunsch'have shown that the sugars under the influence of hydrochloric acid in the presence of alcohols and oxyacids are condensed to polysaccharides resembling glucosides.' Of these bodies methyl glucoside, C,H,O,,CH,, methyl arabinoside, C,H,O,CH,, ethylarabinoside, CLH,,O,C,H,, ethylglucoside, C,H ,O,C,H,, methylgalactoside, C,H ,O,CH,, ethylgalactoside, C,H,,O,C,H, and benzylarabinoside, C,H,O,, CH,, C,H, have already been formed. Previous to the appearance of the above papers, Michael3 had described a niethod for the synthesis of a glucoside. This method depends on the interaction taking place between so-called acetochlorhydrose and the alkaline carbolates. T h e method yields only a moderate product and is somewhat troublesome. The process employed by Fischer in converting sugars into glucosidal bodies is well illustrated by the following example : Grape sugar is dissolved in methyl alcohol and in the cold the solution is saturated with gaseous hydrochloric acid. T h e solution soon loses its power to reduce alkaline copper under this treatment and a crystalline product is formed. T h e reaction which takes place is represented by the following formula : C,H,,O, f CH,OH = C,H,,O,CH, H,O. To this substance the name methyl glucoside is given. T h e other bodies named above are formed by similar reactions. Fischer, however, freely admits that although synthesis has done so much in the way of producing compounds which heretofore have been deemed the exclusive product of living vegetable cells, yet in the case of sugars an essential difference still e x i s t ~ . ~I n the laboratory there is produced at first only an inactive sugar which afterwards, by means of special operations, is split up into the active iiiodifications, while the assimilation
+
1 Re? d . c h r m . Ges.. 27, 2473. P H r r d . rhent. Ges.,26, 2400. a ~ u n i p tvertd., . 89, 355. 4 Oration before the Institute for Military Surgeons, August f u r Riibenzucker-Industrie, 23, 185.
2.
1854. Keue Zeitschrift
THE SYNTHETIC FOOD OF THE FUTURE.
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process of plants gives directly the active sugars of the same geometrical series. T h e stereochemistry of the carbohydrates, however, furnishes for this fact a full explanation. If, in the case of an active sugar, by means of hydrocyanic acid, an additional carbon atom is added, the artificial process takes place in an asymmetric way. Since now in plant assimilation the optically active constituents of the chlorophyl granule take part in the production of carbohydrates, it is easy to understand how from the beginning, the formation of sugars with six carbon atoms takes place in an asymmetric manner. I n so far as I have been able to determine, no experiments have been made to determine the digestive coefficient of these synthetic foods. In the case of the artificial sugars many of them are unaffected by alcoholic ferments and it is safe to assume that the digestive ferments would be equally powerless to disintegrate them. T h e direct products of sugar synthesis are, as a rule, neutral to polarized light. This does not imply that morphologically they are so different from the natural products, but rather that the carbon asymmetry is inversely twinned and the product is composed of equal quantities of right and left-handed sugars. Of the natural sugars, levulose is the only left-handed one of any economic or digestive importance. T h e specific rotatory power of this body varies with the temperature, and at 88" the disjointed carbon atoms are so much reduced in position as to show a rotatory power equal to that of dextrose. So far, it does not appear that the left-handed sugars made by synthesis have all the properties of levulose. They seem to be somewhat different in their stereometric relations from the natural product. I n fact, the theory does not require that the left-handed sugars be levulose, but that they be siinply the twin asymmetric duplicates of the right-handed varieties. Lefthanded dextrose, therefore, is an entirely different substance from levulose. For the old name dextrose; Fischer uses glucose, and for levulose, fructose. T h e prefixes l., d., and i., signify left and right polarizing and inactive respectively. I n one case, however, he has discovered a. d. fructose as well as a. 1. glucose W e have seen how by slow and painful steps and by round-
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HARVEY W. TVILEY.
about ways the synthesis of sugar has gradually progressed until products containing nine molecules of carbon have been obtained. T h e ordinary sugar of commerce, saccharose, contains a molecule with twelre atoms of carbon. This sugar, however, can not be strictly considered as a dodekose, for it appears to be the product of the condensation of two hexoses. \\‘hatever may be the true theory of its composition, whether wliolly of the aldehyde type or a hybrid aldehyde ketone, yet its structure is of a higher order than the simple hexoses and it has not beeii foriiied artificially by any of the usual processes of synthesis. I t has remained for an inventor to take a short cut across the synthetic field and make saccharose per saltum. Jean Ercole Pelligrini, a citizen of Italy, residing i n France, has taken out a patent in this country for making sugar i n a thoroughly direct manner. Ethylene gas, carbon dioxide, and steam are admitted in proper porportions to a cliarineled cube of pumice stone, impregnated with platinum sponge. T h e carbon dioxide and ethylene are used in practically equal volumes and the steam ad libitum. T h e pressure is so regulated that each gas will gradually diffuse through the whole porous platinized space. T h e operation is continued for about half an hour slid “ at the end of this period ” to quote the language of the letters patent, a sirup containing froni twenty to tweiit>--fiiTeper cent. of sugar is withdrawn.” A sample of the sirup submitted with the application for the patent was examined in the laboratory of the Division of Chemistry at Washington and found to be sucrose. That it was made in thenianner described, however, is a matter which, to my inind, requires further demonstration. T h e exaiiiiiiers of the Patent Office were, nevertheless, assured of the genuineness of the sample, by what proof I know not. For iny part, I do not believe that a single molecule of sucrose can be made b>- that process. Some simple organic acid might be produced in this way, possibly some inactive sugar, but where sliall we look for the stereochemical asymmetry which is so predominant a feature in that complex molecule which we call saccharose ? But for the sake of argument, grant the actual production of this substance. T h e price of a pound of carbo11 dioxide is far ‘ I
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greater than that of a pound of sugar, and ethylene is still far more expensive. If the process of Pelligrini really works as well as the United States has certified, the sugar would cost nearly a dollar a pound. T h e whole process, in my opinion, may be classed with the electrical refining methods so successfully employed a few years ago in scientific buncoing. A full exposition of the fallacies of the method is given by Maumene.' In the foregoing pages I have attempted to give a synopsis of some of the forms of organic synthesis which would enable us to come to a definite opinion regarding the possible production of artificial food. T h e prospect, it must be admitted, is not a flattering one. First of all, it is seen that all cases of successful synthesis from an economic sense, belong either to the class already mentioned, v i z . , retrograde synthesis, or to a process depending on the use of already existing organic compounds. In this direction chemistry has a wealth of future achievements to offer commerce. T h e changes and modifications which can be made in natural products will continue hereafter, as in the past, to present to chemical science problems of the most promising succcss. As in the case of the polysaccharide starch, from which a simple hexose sugar is produced of the widest use in the arts, so with other organic products of the field, many victories in retrograde synthesis may be won. Chemistry will show how to make many foods more useful, and in the way of cooking more nutritious arld palatable. I n respect of the direct or indirect union of the elements into successful food products, there is not a single instance in all that have been cited to give any hope whatever. In the way of economy the simple synthesis of hydrogen and nitrogen to form ammonia has never seen any chance of economic success. Here in one way, at least, synthesis might help to increase the stores of food. Nitrogen in ammonia salts is now worth eighteen cents a pound to the farmer. A simple synthesis would niaterially reduce its price. I t might be well for the ambitious chemist to begin with ammonia before attempting albumen. While the scientific difficulties are less formidable l j o u r . &Fad. de S u c r ~35, , No. 4.
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than the economic ones, yet they are apparently unsurmountable. A single pound of synthetic sugar must be worth many dollars, and we do not know that it will submit itself to digestion. T h e complex molecules of albuminoids and starches seem to tile to be beyond the reach of chemical handicraft. There is no possibility of niaking many of tlie nutritive constituents of porterhouse steak, much less the iiiixing of them into an attractiire and tempting forin. In the field of scientific research, however, and the light which will be thrown on molecular structure, there are no limits to the triumphs of synthetic chemistry. As the periodic law among the elements, so the theories of stereostructure, isomerism, asymmetry, and condensation have led and will lead to the greatest discoveries. When the irivestigator is once convinced of the possibility of any compound he will never cease to look for it until its discovery crowns liis efforts. -4s the disturbance caused by an unknown body in space leads the .astronomer to train his glass on the unexplored depths of the heavens, so do the missing links in molecular structures incite the cheniist to renewed exertions. This fact is beautifully illustrated in the case of the carbohydrates. I n tlie last few years there have been added t o the number oi sugars known to be produced by nature, inore than twenty built by synthesis. Rut large numbers of possible sugars are still missing. According to Fischer,' every asymmetric carbon atom in a carbohydrate molecule makes two forins possible. There can, therefore, be at least eight hexoses, and each of tliese is optically paired, making sixteen i n all. Ten years ago only two of like structure of this number were known. Now ten have been discovered, and six yet remain unkno~vn. Of the pentoses there are eight possible forins, of which four have beer1 discovered. Of the thirty-two possible heptoses, only six are known, and of the 128 nonoses, only two. Since the possible nuniber of conipounds increases in a geometrical ratio with the addition of carbon atoms, it is seen that the field for discovery is not soon likely to be exhausted. But the molecule builder, it s e e m certain, must take his stones from Nature's quarries. H e may fashion and change them, adapt them to new uses aiid endow them with more 1 Xeue
Zeitschrift f u r Kubeiizucker-Industrir.
23,
r@.
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valuable properties, but he can not make them of the raw original materials. Schorlemmer in the revised edition of his Development of Organic Chemistry, while taking a very sanguine view of the future progress of synthetic chemistry, does not expect it to interfere with the farmer. H e expects, at most, morphia and quinia to come from the laboratory instead of froin the poppy and cinchona. Roscoe says : “ But now the question may be put, is any limit set to this synthetic power of the chemist ? Although the danger of dogmatism, as to the progress of science, has already been shown in too many instances, yet one can not help feeling that the barrier which exists between the organized and unorganized world is one which the chemist at present sees no chance of breaking down. It is true that thefe are those who profess to foresee the day when the chemist by a succession of constructive efforts, may pass beyond albumen and gather the elements of lifeless matter into a living structure. Whatever niay be said regarding this froni other standpoiiits the chemist can only say that at present no such probleiii lies within his province. Protoplasm with which the simplest manifestations of Life are associated is not a compound but a structure built up of compounds. T h e chemist may successfully synthesize any of its component molecules, but he has 110 inore reason to expect the synthetic production of the structure than to imagine that the synthesis of gallic acid leads to the artificial production of nutgalls.”’ It seems strange, therefore, that one of the most eminent of living chemists should have so unequivocally committed himself to the doctrine of future synthetic foods. I n an address before the Society of Chemical and Mechanical Industries in Paris, on the 5th of April, 1894, Berthelot publicly proclaimed his theory of the coming suppression of agriculture and the substitution of synthetic foods for its products. This theory he has more fully elaborated in McClure’s Magazine for September I 894. T h e accomplishments in synthetic chemistry on which he bases his predictions are essentially those which 1 Presidential
Address, British Association, Chcm iVcws, Sept.
2,
1887, p. roo.
Ij 2
HARVEY \V. W I L E V .
have been set forth already in this address. \l'itli proverbial European provincialism, however, lie fails to inelition one of the Fisclier's strongest of the arguments he might have used ; sugar synthesis. T h e wildcat process lately patented i n this country, however, as well as in Fraiice, for making sugar by the condensation of ethylene receives favorable mention and 110 doubt is entertained of the speed!. niaiiufacture of sugar on the largest scale synthetically a i d that the culture of the s u p r - b e e t and sugar-cane will be abandoned because they will have ceased to pa).. T h e struggling sugar planters of our own country who during the present season have been making sugar at a cost of four ceiits a pound and selling it for three, will bear witness to the fact that this happy period has already arriIw1. T h e sj,nthesis of the dyestuffs, especialll- of alizarin and indigo, he cites as exaiiiples of tlic destruction of an agricultural industr!. bj- chemical achievements. H e dwells and very properly, on his ow11 work in the synthesis of fats as evidence of what may be accoiiiplished in that line. T h e beefsteak of the future may not be identical with that of to-day, but it will be a tablet of any color or shape desired and will entirely satisfy the epicurean seiises of the year 2 0 0 0 . Chemistry has developed the whole scieiice of cookery arid flavoring and provided all the utensils of t!ie kitcheii. It remains now only for it to complete its work and furnish the food itself. E\:cn at the present time, according to Berthelot, tea and coffee could he made artificially if the necessity should arise. T h e caffeine of the chemist has the following genealogy : Carbon and oxygen beget carbon dioxide. Carbon dioxide and chlorine beget carbonyl chloride. Carbonyl chloride and anirnonia beget urea. From urea conies uric acid. From uric acid is derived xanthin. Xanthin yields theobromine. Theobroniine yields theine or caffeine. From this pedigree it is concluded that tea plants, and cocoa and coffee trees will soon follow the niadder ahd indigo plants into econoniic eclipse. Il'o attempt is made to compute the cost of the caffeine necessary for a single cup of Java; and the fact that caffeine is only one of its constituents is naively ignored. zjzk.,
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Tobacco also is soon to follow because something resembling nicotine has already been made synthetically. While nicotine has not yet been made synthetically, its near relationship to conine, the active principle of hemlock, which has been SO formed, leaves little doubt of the speedy accomplishment of this desirable end. In regard to the synthesis of food products directly from the elements attention is called to the following points : By means of the electric spark acting on hydrogen and carbon a t a white heat, acetylene is produced. Acetylene will coiiibine with another atom of nascent hydrogen forming ethylene and marsh-gas. Ethylene can be made to coiiibiiie with the elements of water forming conimon alcohol, while marsh-gas in similar circurnstances, yields methyl alcohol. Acetylene with nascent oxygen forms oxalic acid. Acetylene in contact with nitrogen subjected to the electric spark fornis hydrocyanic acid. Acetylene and oxygen in the presence of water and an alkali form an acetate, whence acetic acid. “ I also found,” says Berthelot, that ethylene under certain conditions could be transformed directly into benzene. Here then we have seven familiar conipounds of wide utility ; acetylene, niarsli-gas, alcohol, oxalic acid, acetic acid, cyanhydric acid, and benzene, to say nothing of many others which I niiglit mention obtained from these elements direct. N o w imagine for a moment the enornious number of organic compounds into the constitution of which, according to regularly acting laws, these seven different conipounds enter. There are six different families of alcohols alone and each one of these families embraces a greater or less number of special alcohols. Over tlie whole field of organic chemistry the mystery of possibilities extends. Its combinations and intercombinations are so liinitless that we can only work on regularly to ends that it is iiiipossible to foresee.” According to Berthelot, the fields which are now defaced by agriculture will be beautified by regaining their natural covering atid the earth will be one vast park of pleasure and the cheiiiist the great conservator of the human race.
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HARVEY W. WILEY.
h synthetic climate will replace the capricious one furnished by nature. Winds and waterfalls will provide power and light, and the bowels of the earth, tapped by frequent wells to a great depth, will supply the superheated steam to turn the winter into spring and to bring together the pole and the equator. W’hen these predictions are read we first think that Bellaniy has turned chemist, and by reincarnation in the shape of the great Parisian Savant has thrust upon the scientific world a xiem edition of I ‘ Looking Backwards. ” I n all the instances brought forth there is not the slightest approach to anything to justify the prophecy of a period of artificial food. T h e few cases of synthesis in which the products approach the composition of anything digestible present such insurmountable difficulties in expense and supervision as to render any expectation of reaching econoinic results utterly futile. In the great majority of cases, as has been seen, the process of synthesis is conducted on illaterials already organized by living cells. T h e eiiornious cost of building up any kind of a coniniercial, synthetic organic body directly from the elements is such as to render it, in my opinion, utterly improbable of successful achievement. Even if food products can be formed in the crucible there is no reason whatever for supposing that they can ever play any r81e in an economic sense. T h e untold billioiis of laboratories which nature builds are infinitely cheaper i n construction and operation than those filled with platinum aiid porcelain. T h e sun ignites the crucibles of nature at an expense far less than attends the use of the city gas works. T h e director of Nature’s laboratory depends on no endowment nor legislation for his salary and his bills for supplies are not disallowed by any board of auditors on the score of economy. Night and day his patient faithful assistants work without thirst for fame, without hope of reward, They fight not for priority of discovery and their anonymous papers are printed in rich profusion in the great Berichte of the universe. T h e chemistry of the chlorophyl cell is far more wonderful than any of the achievements of Lavoisier, Berzelius, or Fischer. It would doubtless be a solace to the weary toiler in the sun to
THE SYNTHETIC FOOD OF THE FUTURE.
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look forward to a time when he might lie in the shade while proteids were pricking up their ears in the condenser and fats frying in the scientific pan. But in the days of the far future, while Berthelot will still be honored and Fischer praised, the farmer will be found following in the furrow, fields of waving grain will brighten the landscape, and herds of kine graze upon the hills. Mcm beys of the Sociefy : According to the provisions of our Constitution, the time has arrived when I alii to take my leave of you as President of the Society. I thank you most heartily for the honor twice conferred upon me of presiding over this great organization. It is only fitting at this moment that I should give a brief account of my stewardship. One of the most gratifying features in connection with the history of the Society during the past two years, is the increase in membership. I n two years, according to the data furnished by the Secretary, the Society has more than doubled its membership. Our niembership now is well up to the thousand mark. I should have been better pleased at this time to take leave of a membership of fully 1,000, but I feel sure that this number will soon be reached, T h e JOURNAL of the Society has fully kept pace with the increase of membership. T h e volume for 1893 contains 720 pages, devoted almost exclusively to original articles, of which 98 appeared. T h e volume for 1894 contains 891 pages, exclusive of proceedings, and 158 original articles. I n addition to the copies furnished the nieinbers of the Society, there is a large number of subscribers to the journal in this and foreign countries, so that the total circulation at the present time is over 1,000. I t is recognized as a leading chemical journal by the More than thirty of its editors of foreign periodicals. articles, during the past year, have been reprinted wholly or in part in the ChcmicaC News, and a large number of abstracts has appeared in theJournal of the English Society, the Ben’clrte, and the Ccntral-BCaH, in which, during the past twelve months, over 100 abstracts of articles from the JOURNAL OF THE AMERICAN CHEMICALSOCIETY have appeared. These are figures which are very gratifying to us all.
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T h e prosperity of the Society has been due to united action ainong all its members, and a,deterniination to niake it a success. Local Sections have been established during the past two years in Washington, the Lehigh Valley, and in New Orleans. T h e chemists of the Pacific Slope have also expressed a desire to unite with the Society at an early date and establish a Local Section. There are inany other places where tlie meinbership of the Society would justify tlie establishment of Local Sections, and especially is this true of Baltimore, Philadelphia, Boston, Cleveland, and Chicago, and it is hoped that speedy action may be taken to secure these desirable results. To the editor and the Committee on Publications the Society is indebted for energetic and systematic work in increasing the efficiency of the J O U K N A I , , but the efforts which these gentlenien have made would have had but little success had not the iiieiiihers of the Society throughout all parts of the country come forward with contributions of papers. There are often good rea. sons why a paper on anj7 particular subject should be published in a particular jourtial i n this or otlier countries, but as a rule it seems to iiie that American authors should first offer their papers to American journals, and if this rule is followed it is certain that tlie journal of our own Society n-ill receije a fair share of the contributions. \i'e n.ould not desire to exclude from the field any other journal, but we are justified iti asking that due consideration be given our own journal b y our nienibers in the distrihution of their papers. T h e American Chemical Society represents .iiiiericati chemical science as a wlio!e aiid therefore it is desirable tliat tlie journal of the Society should not becotne the organ of any particular branch of cheniical science. "lie editor and tlie Committee on Publications have kept this end in view in tlie distribution of the articles and have endeavored to put into each nuniber sonietliing of interest to many of tlie special departments of chemical science. Our doors are open for the entrance of those engaged in didactic chemistry, for organic chemists, for technical chemists, for agricultural chemists, for mining and assaying chemists, for general manufacturing chemists, and in fact for every braricli of our great science. T h e journal baing thus cosniopolitaii brings to every
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chemist not only matter relating particularly to his branch of study, but also a general idea of what is going on in other fields of activity. H e , therefore, who desires to keep abreast of the work of the times and avoid becoming narrow in his views and practices, can not find a better means to this end than membership in our Society. T h e American Chemical Society has no quarrel with any chemical sect or any institution of learning, but will endeavor to make itself useful to all. It would especially seek to foster a spirit of scientific patriotism in this country, a belief in American science and American scientists, and to diminish, to a certain extent, the blind worship of foreign institutions which, in some instances, has been so characteristic a feature of American workers. I would riot say anything to discourage a young man froni\seeking a part of his education abroad, but I would certainly encourage foreign chemists to seek a part of their education in this country. I t is not quite right for the United States to contribute so many students and so few professors. While the American student may find benefit from a course of study abroad, the foreign student would find equal benefit by a residence at some of the great institutions of learning in this country. If professors of chemistry desire to attract students from abroad they must recognize t h e k own country in its scientific institutions. They can not afford to remain outside of the great organized body of American chemists and to send their contributions all to foreign journals if they wish their own institutions to grow in favor at home and abroad. While we are proud therefore, of our large membership, it is evident that for every one who is now a member there are at least two who should become so.
There are nearly 4000 men in the United States who are engaged directly in chemical pursuits, and it is not too much to. ask that at least fifty per cent. of this number should become affiliated with the American Chemical Society. We will not consider that we have attained our normal growth if at the end of the next quinquennial period our membership shall not reach fully 2000. To this end let each of our members pledge his word and exert his influence and the work will be accomplished. I can not close this address without expressing my thanks to
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the Secretary of the Society for the efficient method in which lie has conducted the work of his office, arduous and exacting a s it has beeii, and to the Directors and Councilors of the Society for the support which they have giveti me i n all matters connected with the executive conduct of the presidential office. 111the little which I myself have been able to do, I have had , welfare and prosperity of the in view only one object ; ~ i z .‘the Society. I t may be that in some cases offence has been given to tiieiribers of the Society by the niaiiner in which my work has been done, but I ani sure that those who have intimate knowledge of the inotives which h a r e actuated m y conduct will bear witness to the fact that such offence was not given with inalice or mean1ng. To m y successor I may say that he will find the officers, councilors, niid directors, reinainiiig a s they do mostly unchanged, full of 7eal in the work of building up the Society and ready a t all times to support him in the conduct of his office.
THE DETERMINATION OF PHOSPHORIC ACID. B Y if. I’EXl1lSKTUS. JIJr!
‘ 7 , ‘89j
HE method of deterniiiiing phosphoric acid by the alkali-
metric titration of the yellow precipitate, has been employed, lately, by a number of chemists and has been made a subject of investigation by the Association of Official Agricultural Cheniists. A report upon the subject has beeii embodied in its last bulletin. There are a few points regarding this method to which attention should be drawn. 111 preparing the standard alkali its strength is, of course, established by testing it agaiikt acid of known strength. I n doing this, it is important that the indicator used should be phenolphthalein, and not methylcrange. Potassium hydroxide almost invariably contains alumina, and such a solution gives the neutral reaction with methyl orange before it gives it with plienolphthalein. Consequently if methyl orange is used in the staiidardizing and phenolphthalein is used in the titration of the
